SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '804f91e79b7f3f3bd3df0d329a4db15a246fc64065e9e7cacb7545c18b6f21b5' 
  AND token = '1bFxIta0DgwuHRTAX0FKkvXI9BpXoCxwBJXgmLm3Yso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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