SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2641a24fa6b82a809075507d39850b71f0a6418698f109ad5389d279bf96d577' 
  AND token = 'xFi8H9MkFnWXn9OjoU0cQZvbvQCSRUzVcBa+5xRjsPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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