SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01d709e468172547dc9497547a5b237379a5c3ed980381959530afad6b6cca32' 
  AND token = 'j1ApXKqpdmutivM9BwFmtFa1mDHPEHhYenBW7uokbt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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