SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8c8ebdc4b8d04170ebe8bf42eb72c356afce5193098cf66f0ae353eb94d7aaa' 
  AND token = 'q/CxIRY2kqjl8BKZuzGedOEXTqXyfZJjkdNV3gmo6Kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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