SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cca3bf7d523118369df34f0515e6b54e5968a4a0dbac6b389d2f072bf187b6fe' 
  AND token = '/0zL6duxLhKeKslRkEA53TJS9w/DXvz+hRdkpaGWDzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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