SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95283b03c20b0d19f484ff8cd2ce34b2f29d18a1cd92129853fe99db5302c434' 
  AND token = 'krzKoHdSJjzef3k8HZaXlqpgG5DI5VUpj3DImCt7mu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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