SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b33cf11d5f9aa920ed74a4d87db2f90e253f04b9035413543c8550261d2fbc5' 
  AND token = 'Nwayh09MAQHGDyN5sqZNUcWMbUUe4/gqRTE6bWOFZ8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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