SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '485e21c7aa50b660911f21482a408292ba03f517cd603ada567503e6bd82c993' 
  AND token = 'Vg+sqa/jAaQHCnAHV+X4T/XiPdesjfKL2hEPrXhGp1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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