SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24846aa8745e80413782a5da8641aaf06022bc66ac2d63b0d1e440b13410ee9a' 
  AND token = 'n3RyRCtRCLXGiGqtKlJ8A1yH6sk7slsE6DsaKJjfX/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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