SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '614368b30492acbcf5c07d50986f869973a862c2986254ca4180bac3757618a0' 
  AND token = '4vs1iMjhp4hBnhGWdvavU3VOK+/LyT8hEZs/TJWPCI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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