SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b679c042e91563dfa25819451f730704b12b86ca02b0d04e97b0ab52cf36d25f' 
  AND token = '/jrudYmjwIT5AZtcYPnbKFwETCJpK2MDdL4kDLxWgYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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