SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06df87a210a5d012abfcc266a3f938e517092873f1321fd54618b4eb862c3192' 
  AND token = 'tNi4ReEdNNi6JE7NbTlfXd6DZCyXNge/kFnzpVfCSoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}