SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a10f739daa6d47ce52b47e244fba4cc14e926ca0d59d53ae19a42c33f0ffdb3' 
  AND token = 'BAvFNn2wC8gPb/xaY54wRlJdkEsWc437xMmWilo9QE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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