SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ae45db299d320723a99601d20eaa0a693755cb470daedcf97ee13bb8068e13b' 
  AND token = 'oVDn1Xbvk8Nh9evKla3NqVj/FiUzB84AiXboSXPq6CQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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