SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'aab5003fc9ee644b1dd3f5f64c4afa36ef564a4117b9c660932c3b5b160364a1' 
  AND token = 'fmSIH33dBmTWyFaqFXavGRrZYClscODLs/6EEs2+jQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00201

JSON explain

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