SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3001781ca549f2ba916ba3ba8fa56f2c6635683f24ce471ee747c2b87571e785' 
  AND token = 'KHNYOwE/If9OnORBeLdM4wfn/iGn1P1NZfakFuR4ldI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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