SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f71f4faf581ed45502df3989d048291135d9bc241809ef07ef3567dacc6fde48' 
  AND token = 'QE7g9s8bm7Siq9nEqnlPQVpXL1c4gTP7Qila0okCxxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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