SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c1b2a4b84a4a3462aa45546ce338b611de39f51fb198c1f03b7024caeb893c6' 
  AND token = 'IDx2Jr7wfFyxTUMTj99E1WVYytM0zWVHfSEyyr6h/nM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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