SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35179363037dc5aedc8c08ef321c13e13de2a1a7a6c42e87a042abd6b550a2ec' 
  AND token = 'VH76dZNoYjrQmjZznLV+kQLT1Kpo69eQeakaj86GOJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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