SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '153b86e1cf7ff2a7e959775c87ca7ef79d86384770b7e5bb1b455f849aec5071' 
  AND token = '+hk/FBUzuBUjRAH5cIisxBlnBfpb2zgdRiw1PgqpOvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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