SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bda3be3179ceb56a8a81426d4e5d3bae875a37555eac437b50c84f4428976284' 
  AND token = '2ZyA7BkeTdq1EmaTjvOyhmRyYI8+OXJVQCG6JRGSg14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}