SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '713ccb286c7f092a02321d055aed2471de0e25396dc3b087e08eb2657c5282b3' 
  AND token = 'IU5lYvxiRqspD3ZRYjUz/l2/hBlRvcGiR5BLNSeixuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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