SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '446858d9ee43d68f8e4b1ef2504cd0dd00388d34908814829b97a4c8ec6e5882' 
  AND token = 'EDMTGuoruW5rEdaWoowEX8SiABngAWtnpGWCTahcTUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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