SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e389f102e7ee470fa4351338d963601ef9bd366884887d6d15e8c14d134fbe84' 
  AND token = 'aJdIFGIYObkJk6ZWn+StJtcffFChOCfJa0APRBMTreQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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