SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccc8fa78aa4462c8d7bc2dcd43e9c25bba243695741a12da9de9ad9c888e5956' 
  AND token = 'OYHLE2oCuetzRXow+ot/fS9fLIsa1AswpQzLbLM3UZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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