SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76f0ac0ca6d521a3b2b9be3910547d0a4b4398941fe637e8885febe5db58f556' 
  AND token = 'd9qekvWKj4wlS0nJnvk9joR08Bm+FpPoH59Oncxu5z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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