SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70ce28629514f4167029d8a68524e55c7fdb2cf76c92ae59e9b313282b17a262' 
  AND token = 'F164zZtM4KfQP9XugRJRS/8FzGL+D29xs+wLraS2+qM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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