SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5679f9158e5c3d152399a4dd3b64f7547512ea749f91018a47915b1990925b8c' 
  AND token = 'E9NnSojkvJOxO4e1tL6ahkvYAT4iCs5fRmou6LmSdio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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