SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf03f809ec1a73ba5cd73f61093080ee579ac3bca7ea122cea8550eafc797c9d' 
  AND token = 'azzgrvWdN7NiS7/lnbnl7bBIgo7A+5axEEmvaHl0fmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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