SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4dd4379e5db3b1e786cfe5b2646230e05e04ebd6e9b773e7a52babdd047513f' 
  AND token = 'Nm9O8VuTe7joIuhLpJGHmG4S+FY3lnPS5/H/GASvKYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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