SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26e4c28339a755205dfffe562777966b8b03fedc3e66fcbe14606121cb2ab8d2' 
  AND token = 'SJO0hXi9LygtWj/cCch1VZQAHaCGmssjkkJ9ZQ+bGHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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