SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efad1afc28fc6958362b7a72bff9d1d6f27397edeb48a870b3dc028fa0d6d1ef' 
  AND token = 'YfsLIMRHwuZR9mSgsrk7A8UePb6A6Ohl2WNoGyl31kA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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