SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e454f517b3ed99137f32bd2d5d5843dfa6a97bc5de0a99371a6f8a1a8e1e6ee' 
  AND token = 'lQt1eBbF+Qy8w84zNXJguLPXq9NoLHtIKGvwg5JWnXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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