SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0a0e50fcf232bc6bbf18c923b37df159397addad008e058317c46a93faa5347' 
  AND token = '2jkApQqLvlDYiAjnIFaAUiFjzhPmoztwJX0sVyMMYWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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