SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3f6087c6dcae0ccb576c7f9513fa067580c66a937cd02e60c95589778c3e4d04' 
  AND token = 'tmoyt9lBuHIZrIUqt8OER8HRvKKvzzQmLbUyfxJhr8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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