SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05776bf854b9b1336d9c0c18a12459276e015209bb018762cee06e68a745ee93' 
  AND token = 'b3GFPFTHmbEJDI6JXGPlPifTY7xyQyF8NlweBR0Hgjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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