SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bcecc4cbaa389fe8a1ccddd2b9298b0a1d337b94468eca4e01d14cc2a2344fd' 
  AND token = 'InM+CKiM5kM3vUz/VugA5Gxxvkc8bv5Mxi4QyfLIaaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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