SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9b3e3cf4cace546715cde51d1057d87fef56f1bed757b5269f356e55fe47b1' 
  AND token = 'bl3m8NlM788Skf1lBRmmkGhP7mUg1N/jgTxKXVKFquQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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