SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '653a4e60440baca6510718d2c341e4fd62e9c867f76a0812e5ac3cbb4fd73401' 
  AND token = 'IK2g2leVNU3BXJQUhhUdxffhATl2W7goIqd0TX+zjYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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