SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f09918d99f227d43cb7059a3dd59bf31e9e527d5f82298c8f15da2cefe355a45' 
  AND token = 'E7mbJBAeKsbG4FZKTdyJnh9wRmfNJCVAeoVQZotkXxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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