SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '38607bf7b183d54f6571e9bb563458b2b9d574d37fe3d03d541454bb7813be45' 
  AND token = 'lN3qSKw+S1u+hV5xNmW6k9sw0JyGpFLx+nIKDjZoGwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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