SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '453c70181155f23f8dce68ba6d5dc78bf2d6f4a3e7f0bbd1093a2c8615e8d1f2' 
  AND token = '/JH7ThzG1z8pv5nsZLpnjfJu3jwTzAnaBk4DSbVHRdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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