SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a537e6af0b077f7ad475ec5c37e360cbeefc1bc0544ead5ee960e1ed6fab37c' 
  AND token = 'mCBktwcDwyuqyZRp6QOG9xuxQlD3OWipAXfdV0TKLU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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