SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6976cb5ffe0a1965f4fd21bc1fbb4a1f41a033dc914f6c42e19e92ace78a55dd' 
  AND token = 'tEclyZYB8lVagTtC/jXSwWI/l4bRJB+poJcPH2U/vPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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