SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e58463e901d40dedcdd4984924bb8adaf56355685cc8ecd7bf9dcd1689a8d338' 
  AND token = 'gvcLfiStzAWXVUNLZh1nq7fV88ORbREAQ6iBoPuo2VU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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