SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74762f4602f50137b8a631b53d3f23fae47544e26537c0e9937f2e4ac0a55b9d' 
  AND token = '3cjSfKNUley8YgsKosBVLFIUoww0gzPJIXfV6YIrXkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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