SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a278a96edb527dc64347254f179ffce7c0d4731e823c65c0ae207444a7ac7552' 
  AND token = 'rJqRGOPvVK/Qbxq1yfNf/kqZqqZ/bIx3R59GpgYuMl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00080

JSON explain

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