SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f306e1ae52a663751246d642c182c39238d657bf026133693c4aa5761408088' 
  AND token = 'KhPEupJ4m3Ade7EBNslkK1Mub5L+2XMh5pty/dW3JYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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