SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1262cea57edd48e95c63edb1831394c1d8686a9d6b0bce10999dfa8b53337d52' 
  AND token = 'ADF5/pjRcsTjA3iXGi01eUpBQR6q1L+IJMXYuSStMko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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