SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '790199ff52e37b47ee5844ef445a78c23f481b34b3a3a4aadc160218fd44aa73' 
  AND token = 'o1EzB1nQcZ8pxZJBHjvsH16KlwKj8csVmhOo4fy98io=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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