SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa6820be26458599a64ee71c2528d5c925ab73412cc3864c9f16898830ebccd9' 
  AND token = 'YLRSOCDvqNTYiXycil8S2ERSfM+869BdLmHnThgcjc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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