SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '233bb36e7d16cd71faa0154e2dd493f556b2296138cf1518f122d5fcfadbce2e' 
  AND token = 'HR7oA56lBK/3VionHx/CNHT84mng8LGY2owjbKH0+pE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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