SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc92a16f79ff1336499aebd87201424d8820f0939a611178fccc89a7ab039d33' 
  AND token = 'Q1AYTt0ia37QLZ3LDqO9U6p9A0kcTZ53WPMxWlz3ahE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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