SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dcd67f0bfed9411b83822bcd31beda51479f67312bd5aef5c7bb20bb01963403' 
  AND token = '0myfIPm/gzUuOHQ8UhxMkS/zAJuPcOnM8pts6RKgMUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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