SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fe37f8b3d50f99db96da018c57a48cc6acc0110750e9391cdba125cde724633' 
  AND token = 'OT8l/Z28YPE6DTysI05StTcTGUtiCnltBjxTToeX2II=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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