SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d082bda6e0786d4231f3fda49f209ecf6d0f011f6a6dc3a191cd29fa72cb32e' 
  AND token = 'jvEoP5fmjdGiudmYfrVlRQYg1EgvGvKCffflM5zqBdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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