SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93f24f8c4a66230a31f102c018389135484f212e6473faf333b9888bf88e3aca' 
  AND token = 'lVb0TubMvL1v3J/GtoMSGvglWSmwwPjZhTvBCAvxpmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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