SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80db29cbe2e8b4bbb9f3479cd5f21a821c40028738ca0705e7fdd41be21ebda4' 
  AND token = 'dEzCXctiM56lsX0SNVSdcdaedsC/ij551/h0onRekk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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