SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73f5e1781777df00519e5030f3171150dbaf3317e851754e6da6ae3389aa7530' 
  AND token = 'U9BVp1mJavifCoZHjRglHY7vqmdyq4lD/LVLMLhpppI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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