SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca06e9728201a1f4061b31ca84c2caee37a249516204594e4dfb2646c2e03a55' 
  AND token = 'AnaSzUjJ/BcFY3wNtw1G8BZBOBaOtK4v1S5WgZk+GHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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