SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '495ccea3cf800905a0a88bc22651caec3e1b289202f73416119facd686fa6a38' 
  AND token = 'NLx6u2kZxKGTYC/oElJAae3/28mHbSKMP9H+2LvqpJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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