SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46a89f47c9b4bf8f310bfdf4143a1789d91c387ee5a7df41815cef39ddfcda7e' 
  AND token = 'SIUJ44TY6pfiAZ4GxyH05f3BYOmOh9sRsdyBHu3aNSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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