SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e652709af999781b72a78d7f6c2a83303dff67cefee140f15c19c66de0cc7f1f' 
  AND token = 'egdUPCPsd/Bho18dhev4kKQsvBUvbtjhUBuYYTsKTTg=' 
  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"
    }
  }
}