SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3ee5ff6cc3df4194fad2e816ff7d647580d9578d3ed63fc8334174b42c2e7b4' 
  AND token = 'WTArX6li2Eu2p8jDv5/iXHN9CmOb1ECbPfdvAmDw0co=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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