SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '585bfc1ed8cfdb9b94f29dd5bdba4fbdd472ba322da66cd625846073f7850ce6' 
  AND token = 'QuzTooHkM8stoaG3IZ1JYeBuIqI0epNu3viJl5mFjFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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