SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5f55f42a1a65cf795b9310c2e89de71a1f1a013e0f2d9b36d3278b86b9238e3c' 
  AND token = 'YpRjZ5ZWSKhGhjZq0AiIkN/3ws6sR/H1sy4RRZpane0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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