SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b704b3d0802b3ab74683215df3f9ceb47e05b9f722ee3e5ea9b5ac36fbc6ac98' 
  AND token = '5JDQD4vLo60f8wRnDkp+kH+KznLJ15SSkG/CMuG7lvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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