SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d36e14aaed7de887af2edeeb20537d386df75f295260edce907851258d40e59' 
  AND token = 'gy+CbxotqXmav6VrWiN3jcUkoDoeysvCC1Sh+iKIl74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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