SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abbf72fa84abf75ed8a80952f5e5bee0105f769564b52e2c61e70dd77e79fcae' 
  AND token = 'DOyh2l+ZluLYZOrHTt1pQfqMQLs3ysmKnGjJPwQhEZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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