SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf39825fbfae9bdb4461bf98e5ae24542946da1e7861b73d313d3ddff6328107' 
  AND token = 'CtvOkzIh7yJHemtYhdBeGsubqgi+s6xsTgQdlrCArN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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