SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f092e3ad0bad77a26a67d3f757fcddca5eed3337c327e2b990292e636bd4455' 
  AND token = 'JMMOmmtLal1CKO8mKjJvJqmGHtBvvYxfWvFuhVkP/Gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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