SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05168f425a7d28e0c6185eab570d7d4bd3f9ee8c326b7852bd6a6f14df1589a4' 
  AND token = 'z4YXDpNhrQU4JZSxkAWJ/MCB+vkThWE1LlZEXWS3kKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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