SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebf2f83f76a89a89f059a9856aee76a11a23c516591dffe047fa6aa977a9168d' 
  AND token = 'Nbt+AmNhWfeTQaoN3C3P9B1wbVt1dYzUOtl2F5/zpqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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