SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '178874cec7b37da08c26e45c313e3616965d0842e9638f79bb5b2497000c41c2' 
  AND token = 'CBz4utfabotDjwC/fWp4XRrm+kMVDK4Rv2edLvDlyVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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