SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a9274b27f4d90ef1f71364c6c1de057a88a374f14d76d15336f80a7f064571c' 
  AND token = 'SfLBHo00ulx7jN6LsDNVPR7cmp/6FkYiKRmZl5iM6Qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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