SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd112e009b7f8ae970318e516c477941a63d347a3f855687a1db5f1fde5d02a62' 
  AND token = 'RQ0lOXEMKneAcWBqSD6O8Kagz87fLnqGG1UQ7+3ux6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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