SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d739d668f3b116d106789988188ea8d1fb279212ee0b3121d830c4df359cdb7' 
  AND token = 'JXyqM4beTPzHu2qLfiEqDojZREzSGqzgOqNS1xuMhIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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