SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c4c9de1e65dd97d35db8df348f532c34d1b91a44e643e24d5cab5bcd723d357' 
  AND token = 'Y1+6/amq/ufLJyx4zMx8++mXj9Zvx+Of0VyxgkVP3sA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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