SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84a201a61d3eb1e254abd0b83c64d2a271fb2a6bf72ee47d93622c66df83a378' 
  AND token = '7uvVeVooFVpnmmKBAyoAc/nabD/wpJS9ttqzb8RLOPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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