SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f49f78f9b12749e944c319e2d5406268704c74c7b39e8049cd5ac62b15e55984' 
  AND token = 'dB2SWvsq2LK2yC6nk4KuOqLEXAV/UQnorsDDGG7Xf+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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