SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9c0dbdcefe8d5e5035f224c6d7c8c4eeed8eda3e4f1b7d2c215c0ee4057f087' 
  AND token = 'MYcaKINIR7koMg5ja0ybSbIclomBbtCAaPKA1S4hXcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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