SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7825e369d886409fd6992ed9379321c0ee7ba83df30156564d80f81f549d636' 
  AND token = '/+M5ePnKZV6a9RjAVSduPL1KKt57zuD7fEEYiqmUJGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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