SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f8234d792782a170c6db091b568c1452029c029a5e1954397a61c6dd1b8ceff' 
  AND token = 'PQqppOjZPwM9RUqFx+lWZej6JVv3NO9Ylr1d1ysJDfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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