SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '48ed2d0ef2ca590e32d7f9c51081062a403a2511bbacb3d93abea2e1c016e8b6' 
  AND token = 'SelDy4u1bouFYOQNX6ZHIT7WHcCfWlROzvW8nb+Egqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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