SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e944a7a44a6e3e93f772628b5fdcc7b218f1dc65686420c1560d6ca4f02a128' 
  AND token = 'bW7Ak+l8OSR0XRTdrDLG1OxJtZYoUHVjcBYznnUiJZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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