SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e5c44d2c6c1eac150c71b96b3905781ad3a6ede2187e3ac232042e57639a1e6' 
  AND token = 'YRj48WPftmrMZ3yQbebkzKuXrCctvQrOoCAJaAdxVBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}