SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bebd0d600ece67df3ec87801109facb4f9dd4c2e26bc59ef1c76752c69369c40' 
  AND token = 'NhVbYU1iic38dJ7Ghtrbv+bf+Ix2ebSdm9wTsOG8Pbw=' 
  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"
    }
  }
}