SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae45f014d959185cd62f75043b3b17c2fce231747883cb8355eeac4b8866cef2' 
  AND token = 'ScJmSVFsLhPRZ8oOpfAKl19llXQwxEHeD7rmV+Nk43k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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