SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd59417fdcfc6d98ddda708abc701890ea701101d65e7a3c31c0e3f68dd643b4b' 
  AND token = 'QjV+EQkjwICv5X5l/uGzN4DzQ8d5dP9tRQAU+pRGAIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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