SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6131bb76505211ff3f94022abacfb53b684a5b1a68dfb93314257d669adf68c9' 
  AND token = 'j7grWll55fYO3VEer6O4hUFs9I9T/jLiAiROwcnlXyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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