SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92291ce90b0376458c2d69656bda5c640091385781fa9cc60d60b464f4676e63' 
  AND token = 'WcoMKGRvCDgYX9DoQrAI6Eu/lJzfYNZYelPKPiDCJwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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