SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a744b03ea43d9af9cd17a8bc64a6eb40fb26144fd5d606267ce5339596312c46' 
  AND token = 'GuZz5UFlMsHazLrSjLZu0qjOVHo2XfcDxlHV/XZDP7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}