SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba58a222dbdf4b348e11cb21149ea34d4befc5ea517fb0a7b1c9e9b792114bb6' 
  AND token = 'UMdTQtBop836069bhAlpYoPIUBjAk/M2qvaKnjLRfXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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