SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3db8156ad5822ed7fafbd3b630ff9b03ca509d63b911c96c2a472d628438585' 
  AND token = 'QvgWZZaBtylMqMzlb/7jYb9AoLPKhdW4W7lUrCL5qp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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