SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f53aa9b4ef6d3d740dd78c96dfd75ec185e2ebc340edbc479600e9a25ec16bb' 
  AND token = 'tpno768rwy5JCEhSwIMkJ/NAxhSZhlsxRbztmk1OSak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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