SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd416e7679446a8c94ad7487daf744c376c02fea1be6df0a8a8d82cf0be50050' 
  AND token = 'DbNEcAvvW0x6xGbsWUYPDpgLe4YR5EuZfxMczOFCvF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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