SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '336a6c113807c515390c8cb568151e8fad19fc5375ff1515acf33998637dfd5c' 
  AND token = 'yAEGcJxH/JSfLLX2U/ggCiJFwYUcEt1N0X1ZzNp5iM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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