SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461739a31e52030382856a8eea3667d1785fa3b08b4d68f38c951677fdfb65c2' 
  AND token = 'lKiyArzYRx1Uv5x0OUtCG9cfoBP9TlFnV6VfjrCNuWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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