SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8bc56d2baed1bf49ea004410aee7e41ed23542262083b11364c86b63ea15572' 
  AND token = 'o6higv2aSbM7gXRXKrCaCf7Elfs2l9RhKsxIUZdX9NI=' 
  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"
    }
  }
}