SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e40a4116b6582efdc2b1d459243e67424142206534f2052dcc66cf67133f969f' 
  AND token = 'v6M/7xO2lCmgVa8GKYdTiLSaEMRBLhQo1OJxXhL/Jxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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