SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '698260001350f3c11e8ef0735930346173750e55ee49787ff43cf746ed777717' 
  AND token = 'UsjjafFBRMsrvMmV6yR+Dn1/yskLSUQuotmUvr9zrUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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