SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73baa037a578122bccff7e5c821e52942049bb0b636b6192abf6c0a84ab52651' 
  AND token = 'GOpBVJ8GgAcOcYZTl/DZXFZzNU9P0jgs91G4GX4npW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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