SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33135e5e81864afd788aa5ab4a6e6caf19a6912e53547aceeba9dd43f54c82b1' 
  AND token = 'hHfWU2R2qsyrwVnyJYVaUaJYUr0dvSEYHSZ6GgfC16c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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