SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '137971cbf600afcfcd1e305b56f545590e4cc2d624c877563c6ea66f6086d26a' 
  AND token = 'BJNUJRWgRXaSxpuL0GGIHciiovI+LoziB9OnL7nzZog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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