SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f55f43b825dd75555fb353b8f46478ba7edb7ffd8af82d14dfe5084b74bd9fc6' 
  AND token = 'U4CgSVBDG+lN6SxO0NlcyzU/RAnCSzamudDEpudN9q4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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