SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fd27881d026da8d6f7c97ba4da6878354768ad1f7431e11a8e64ba3b4908bd4' 
  AND token = 'VPr+1wQBsqi/iBzUoVLR7I+SYco2o21FOg8o/AKeQEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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