SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09ad03b102e54cfdc746cbb7986f65c8e25ba968de53be1e7ca837619216db5e' 
  AND token = '/6buIzoTHBVbpdLNBVTgIq/GrfYKs9SnNv+v1pqnKr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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