SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee18fa282306b9e035bf8fa5cf1ebc64f7a77ef39b7a98cdbeca3f611e43ec14' 
  AND token = 'pzReWHu8Ls2w2JZ1LiZavl8w+BYdjZoK1gDACKmuyIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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