SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a73932d4998a8d0d8203efbb8b390d7b2b013f438aed7f1aea81c864caa72627' 
  AND token = 'jKPjpd3sJkpiPKR+BzTPdQcORd8WcTKN0iZPoelbA4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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