SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5d0ed83b1c0a31ac56e5896d49720b88daae795a25df1695afb2eff6c7c59302' 
  AND token = '3TJ+UfNN+TuXntpP71wbXOVL2HAAjUWOjQooFD1DIcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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