SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7572f4589636eed11de226f090bad25ea88f3a236a42d40be8ea78f7e7aed51f' 
  AND token = 'JgFcRZpKAhqC3zxDAbxjfwFVkBVSikTYl2HftPRg9BI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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