SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ce2b51204087797f5d70b69d21c19a1a6f5e28d18d5b6604d2c6a3c789eef99' 
  AND token = 'peMXBnu2bF5KDYDWPHmAJQ7nqhDzm0/wGCwMYi9gy58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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