SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87de55662ccd1d289c7e64d6efd0aceb81c58f5ae659209211c98e8a3a679249' 
  AND token = 'raAAgQo+eyH0u8CxkwyaNYuLjJuT8owzfbZJl7YJiaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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