SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f968b5c7941d7965fc85f7453da0cbe78b2c83b0877ffeb20654553404c6cb9a' 
  AND token = 'WnbyZm+y89jtxRUu2dTuxEE4d1/xuDmnKEMMe5To+9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}