SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '787d6b325b81c2ee981bd5b85dabf5a31264d0a8ea675aed95b76be394e23458' 
  AND token = 'dJpVKsQ3iziv+wRqDPYIZyfOT1OfQT1/RmYuBNpvzPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}