SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a00e48e849bc14e4d945a3895451552b1e294c6857f95ebf8935ec4fd0b9122' 
  AND token = 'm/q5XCT1pxoPhlzU3O6cieEGQAI/etlOWO/tfrTFXd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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