SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbbbce43fdf414656bca894265d898b508e3185ca3053b2c4f9292b955ac8e90' 
  AND token = 'omrCEccbpq/5mTNwraxocEwF6SYxVRUaNc0lmlz6TWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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