SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e306732f737512f39f37484af14a2c20eeba78635fa784db2733ceb5c569c61e' 
  AND token = 'YfGWE6nZk5DF5QQBrXMea7bvZKkeqbpQP8+zKcrFOd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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