SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff2074d851a58c31b21dd2f9067f66e0ff77ee51e9a0bbcce61db8ed487629f7' 
  AND token = 'VBhPVOLiScaL9/j6nWIWk3OVu6KleNxsGGNHa1/Hyfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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