SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83a58125f90351f73ad6d509b76cd22542dd3341387978588d702f5d33f16cf0' 
  AND token = 'PWA/9G37gRDsiTxlCQOa/7+HaiIT0GsjRXW4su+l3RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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