SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dee749783d31c9bdd75450244bceb8f7b3dde95ab905d6f7ffe4af09dee039cc' 
  AND token = 'HF8/qwYTa7yH3JNIZAKOIQJMOEuXqq1YpQsaUgu1CtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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