SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95994ef133e7366b3f167dc5ad26657575825e9d249c0d9fd887befbe285e858' 
  AND token = 'ZJBp6rX3oUYghokv6yOYNm+2UtHGsknVPbTP6H2VfBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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