SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7adebc577e0680146f95eb0644fd2da6cb702fc39283ca8601d0cff74a7e4e04' 
  AND token = 'hn25zINJG+9CwysQ5raP3SMlYA40/iggTOf3Mq5Ww20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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