SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3110dd1375c6373e3f51ff521996207a4c81d3a4ca1b79fd8081bfdc91ab0e3f' 
  AND token = 'hnxPIgRHO+AZiyz9yVwitR/bfj1V/lwu+JmU6kGv0R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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