SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb9b161cc4726b4e9e8313c454b6f99380ba5cb509050530a51c14d51d3268c0' 
  AND token = '/jOjxHeEU2aG28Ul4KczuhllEhnuHM8DsUfPqJxYXW4=' 
  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"
    }
  }
}