SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab759598fc7dd7a38edefee9967f000ba9656dcca2b00d86f67c6feb16cb7f61' 
  AND token = 'tigbjJB/zXUWsWnGErvAXcbuAplY8chIDA10TK2voII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}