SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4191900de8083f30e940f167e889ca4a9e0e8aaa8f71858c973782453b62d608' 
  AND token = 'BOYuxhJdfMPSutcLx/UlM4jXeVXoqdWAkOnBnAWPviI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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