SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '634cdc74d7f5d24c50127d6bd58706fe83c2b463bb281c5e593156cdf7eb8f01' 
  AND token = 'SPz6Ub92z/7zUlq34CkJKZn3vmoQMDZxvszefYXOVpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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