SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7d03e3b79d7d209b9fa0aa27af142e7f4f1a83fd1f4f98e3281151a10c1bb77' 
  AND token = '5eX+TvuNCWdmGSbZZCaqu8vJzJCL1nW9iKaewo0cyPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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