SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf75188a3ee7ce9edea04beee4b98ea3426344971886157db3e32b17aaa2d555' 
  AND token = 'uTM0UfoqkQOrbz+ZPFkKkI7C4UiyXV8vwgKdU4JL3LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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