SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb8f98a11d1c736e837d8e575d17b4602e1335a4a64cb40bcf479f6d4d4e9e8d' 
  AND token = '0grQxkMgdky7v8nnq8Gnau0k8WZ3IfYc8CSmOccPqLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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